A long story
The history of distillation is closely linked to that of alcohol. The mention of distilling devices can be found in the authors of ancient Greece. But these tools were very primitive because they consisted of boilers heated over a high heat on which a layer of sponges was placed which collected the vapors, condensed them and then was pressed to extract the juice. This process, although primitive, has made it possible to obtain a low-alcohol drink. The Romans do not speak, in their works, of distillation devices. They had a fairly accurate knowledge of fermentation phenomena, they made wine, mead and the Germans had taught them to make a kind of beer. What we know for sure is that alcohol and distillation are the fruit of the practice of the Arabs; in fact, the names, alcohol and alembic, originate from this language.
Arab science had the great merit of passing on knowledge of distillation to medieval European science
Water as a coolant
In the following centuries, the structure of the distillation apparatus has changed little. It was only around 1200 that the effectiveness of condensation was significantly increased by introducing water as a coolant. This also allowed for the distillation and condensation of ethyl alcohol, which was the most important distillation product until the end of the 19th century. Where it appears, this cooling mode was obtained through a jacket, which covers the cathedral or capital, filled with water. Michele Savonarola (1385 -1468), doctor of Padua, (grandfather of the Friar Savonarola) wrote a treatise on distillation for the production of aquavit “De Confidencia Aqua Vitae” in which he described for the first time the metal alembic, with the coil, also made of metal, immersed in cold water.
The first printed book on distillation
However, this technique was slow to spread if, still a few decades later, it does not appear in the first printed book that dealt with the techniques of distillation from plant and animal substances “Liber de arte distillandi de simplicibus” of 1500, by Hieronymus Brunschwig (c. 1450 – c 1512) German physician, alchemist and botanist. It was a text that had a lot of influence, of which I report the images of the distillation apparatus:
In the treatise “De la pirotechnia” by Vannoccio Biringuccio (1480 – 1539) a book work published in the first edition in 1540 in Venice there is a chapter dedicated to the distillation ” Of the Distilling Art in General, with the ways to extract the Waters , et Oils, and making Sublimations “. The apparatuses follow the tradition, however the first image shows us, on the right, a serpentine duct associated with air cooling, which functions as a rudimentary rectification column. The medium water is the protagonist in the median basin where the column is wrapped in a few convolutions. In the device on the left the choice is for the coil immersed in water. But this second option does not begin to spread until the 18th century
Distillation in art
The pictorial art from the fourteenth to the eighteenth century mainly represents distillation in the alchemical laboratory through the classic alembic where cooling takes place by means of air, which remains the most common method.
Not obvious solution
The serpentine-shaped manifold solution was not, as it might seem, a foregone conclusion. In the following images, which reproduce the distillation apparatus from the 17th to the mid-18th century, the serpentine collectors immersed in a container filled with water (in these cases the cooling was obtained without water circulation) had a place of lesser relief than more traditional appliances that did not use the serpentine collector.solution.
The technical difficulties of the serpentine
To understand why the use of the serpentine saddle did not quickly establish itself, it is necessary to consider the technical difficulties associated with its production and use. Building long, uniform gauge metal tubes was no easy task, and maintenance and cleaning were also problematic. Formations of deposits or oxidations were difficult to remove.
Johann Daniel Mylius (1585-1628) Opus medico-chymicum: Continens tres Tractatus sive Basilicas:
Quorum prior inscribitur Basilica Medica. Secundus Basilica Chymica. Tertius Basilica Philosophica. Frankfurt, 1618
Jacob Manget Bibliotheca Pharmaceutico-Medico, seu rerum ad Pharmaciam Galeno-Chymicam, Geneva, 1703.
Nicolas Lemery Cours de chymie, Paris, 1757.
In Diderot’s Encyclopedia or Reasoned Dictionary of Sciences, Arts and Crafts, the great work of the French Enlightenment, in which the knowledge of the time is summarized, a section is dedicated to distillation. The very rich iconography, which is reported here in small part, shows us an exhaustive picture of the conception of this art. The images lead us to conclude that, around the mid-eighteenth century, methods and equipment were used in distillation that had not undergone significant changes compared to the past.
Counter-current water cooling is invented
The second half of the eighteenth century will be the protagonist of some changes on the distillation apparatus that will improve its effectiveness in a revolutionary way. This story is told in another article on this blog